The chief objective is to determine ability to control blood pressure by nutritional-hygienic non-pharmacologic means in a sizeable proportion of hypertensive individuals (most of whom were originally characterized as "mild" hypertensives), normalized by pharmacologic treatment over 5 years, in the national cooperative Hypertension Detection and Follow-up Program (HDFP). The goal is, by modification of overweight and excess salt consumption to maintain satisfactory blood pressure levels using no antihypertensive medications. Intervention will include individual diet prescription, individual and group education. A second goal, for those not able to be controlled when all medications are withdrawn is -- by means of diet modification -- to achieve control using less medication (step or dosage), compared to entry regimen. A third objective is, in another randomly assigned group, to assess whether previous longterm blood pressure control by pharmacologic means makes it possible to discontinue or reduce drug treatment of persons (mainly "milder" hypertensives) without nutritional-hygienic intervention. Both groups are to be compared with their status before entering the trial, with each other at 6-month assessment points over two years of observation, and with a third group maintained on drug treatment throughout the trial. The study is a cooperative two-center project (Chicago-Minneapolis), in which both centers follow a common protocol, using common methods and forms with Chicago serving as the study's data control and analysis center. Each center is making separate application detailing both common and individual aspects of the study's conduct.